\ ˈjak How to pronounce jack (audio) \
plural jacks

Definition of jack

 (Entry 1 of 2)

1a jacks plural in form but singular in construction : a game played with a set of small objects that are tossed, caught, and moved in various figures
b : a small 6-pointed metal object used in the game of jacks
2a : a playing card carrying the figure of a soldier or servant and ranking usually below the queen
3 : any of various usually mechanical devices: such as
a : a usually portable mechanism or device for exerting pressure or lifting a heavy body a short distance
b : a device for turning a spit
4 : a female fitting in an electric circuit used with a plug to make a connection with another circuit
5a : man usually used as an intensive in such phrases as every man jack
b often capitalized : sailor
6 : something that supports or holds in position: such as
a : an iron bar at a topgallant masthead to support a royal mast and spread the royal shrouds
b : a wooden brace fastened behind a scenic unit in a stage set to prop it up
7a : any of several fishes especially : any of various carangids
b : a male donkey
d : any of several birds (such as a jackdaw)
8a : a small white target ball in lawn bowling
b : a small national flag flown by a ship
9 slang : money
10a : applejack
b : brandy
13 US slang : anything at all used in negative constructionsIn short, Dinger or Homer or whoever it was who wrote the Odyssey didn't know jack about travel.— Steve Rushin


jacked; jacking; jacks

Definition of jack (Entry 2 of 2)

transitive verb

1a : to move or lift by or as if by a jack
b : to raise the level of usually used with upjack up the price
c : to take to task
2 : to hunt or fish for at night with a jacklight

intransitive verb

: to hunt or fish at night with a jacklight

Keep scrolling for more

Other Words from jack


jacker noun

Synonyms for jack

Synonyms: Noun

Visit the Thesaurus for More 

Examples of jack in a Sentence

Noun I'd buy that watch, but I don't have the jack right now. a Portuguese ship flying the national jack
Recent Examples on the Web: Noun There’s no headphone jack, which will disappoint long-time Samsung fans. courant.com, "CNET: Best phones for 2019," 6 Sep. 2019 Rides, kid’s games, poker, black jack, bars-n-bells and many more games of chance. Luann Gibbs, Cincinnati.com, "Things to do this week in Cincinnati: Aug. 26-Sept. 2," 26 Aug. 2019 The native bird life was raucous, brilliant colored and poetically named—lousy jacks, mulga parrots, rosellas, willy wagtails and lorikeets. David Maurice Smith, Smithsonian, "A 42,000-Year-Old Man Finally Goes Home," 23 Aug. 2019 Swap in Monterey jack, or any deli sliced cheese, for the pepper jack. Becky Krystal, The Denver Post, "How to upgrade your sandwich with clever twists on 5 classics," 22 Aug. 2019 Swap in Monterey jack, or any deli sliced cheese, for the pepper jack. Becky Krystal, Washington Post, "How to upgrade your favorite sandwich," 21 Aug. 2019 One bedroom has a jack-and-jill bathroom with subway tile and marble. Emma Kate Fittes, Indianapolis Star, "Hot Property: California contemporary home stands out among traditional West Clay homes," 19 July 2019 The company, which makes a wide-ranging set of low-cost gaming accessories, has a new gamepad called the Faceoff Deluxe Plus for the Switch that comes with a 3.5mm jack built in. Nick Statt, The Verge, "This $25 Nintendo Switch controller supports in-game Fortnite chat with a headphone jack," 15 July 2019 Three community cards, a jack of spades, a 5 of diamonds, and a king of clubs, were dealt. Daniela Hernandez, WSJ, "Computers Can Now Bluff Like a Poker Champ. Better, Actually.," 11 July 2019 Recent Examples on the Web: Verb Bichette’s onslaught didn’t matter much on Thursday given that 25-year-old lefty Thomas Pannone was clobbered for seven runs in 2 1/3 innings to jack his ERA all the way up to 6.83. Jon Tayler, SI.com, "Bo Bichette's Historic Start to His Career Makes Blue Jays' Future Even More Exciting," 9 Aug. 2019 However, the biggest motive for FaceApp to collect your information is most likely ad targeting, and the motive to make a scary face-aging filter is likely just to jack up downloads so that more people are dumping info into the data set. Kaitlyn Tiffany, Vox, "Anime brings in more than $19 billion a year. Its artists are earning barely enough to survive.," 17 July 2019 Experts say that means auction houses are free to use shills to jack up the bidding. Dennis Wagner, azcentral, "Fake bids drive up prices on popular site Auction Nation, Republic finds," 24 June 2019 Seven days of hearings Hundreds of companies began queuing up to testify in Washington on Monday for seven days of hearings on the Trump administration's proposal to jack up tariffs on $300 billion in Chinese imports. Rachel Layne, CBS News, "Tariffs on China goods will hit women shoppers hardest, JC Penney argues," 20 June 2019 Over time, Russia has continued to jack up the price, and now charges NASA more than $80 million a seat. Christian Davenport, Washington Post, "SpaceX and Boeing continue to struggle with spacecraft designs, as watchdog raises safety concerns," 20 June 2019 And with his boyish grin, cropped hair and stage gestures like proudly placing his fist at his hip, Mendes at times looked a bit like Peter Pan Tuesday — except he was really jacked. Piet Levy, Milwaukee Journal Sentinel, "Shawn Mendes keeps getting better in concert with uplifting Fiserv Forum show in Milwaukee," 6 July 2018 Removal of the cap jacks up annual fees for large businesses, such as the Burbank Town Center, which would pay an additional $100,000 per year, Hill said. Andrew J. Campa, Burbank Leader, "Burbank Unified looks for redo, places another parcel tax on ballot," 2 Aug. 2019 What jacked us up was watching our quarterback dive nine or 10 yards without his helmet. Gary Peterson, The Mercury News, "C.J. Beathard block excites 49ers, evokes Steve Young’s helmetless run," 30 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'jack.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of jack


1548, in the meaning defined at sense 5a


circa 1833, in the meaning defined at intransitive sense

History and Etymology for jack


Middle English Jacke, familiar term of address to a social inferior, nickname for Johan John

Keep scrolling for more

Learn More about jack

Statistics for jack

Last Updated

2 Nov 2019

Time Traveler for jack

The first known use of jack was in 1548

See more words from the same year

Keep scrolling for more

More Definitions for jack


How to pronounce jack (audio)

English Language Learners Definition of jack

: a device used for lifting something heavy (such as a car)
: a playing card that has a picture of a soldier or servant and that is worth more than a ten and less than a queen
: a small opening where something connects with a wire to something else


\ ˈjak How to pronounce jack (audio) \

Kids Definition of jack

 (Entry 1 of 2)

1 : a device for lifting something heavy a short distance
2 : a playing card with the picture of a young man
3 : a small six-pointed usually metal object used in a children's game ( jacks )
4 : a socket used with a plug to connect one electric circuit with another


jacked; jacking

Kids Definition of jack (Entry 2 of 2)

: to move or lift with a special device We need to jack up the car.

Keep scrolling for more

More from Merriam-Webster on jack

Thesaurus: All synonyms and antonyms for jack

Rhyming Dictionary: Words that rhyme with jack

Spanish Central: Translation of jack

Nglish: Translation of jack for Spanish Speakers

Britannica English: Translation of jack for Arabic Speakers

Britannica.com: Encyclopedia article about jack

Comments on jack

What made you want to look up jack? Please tell us where you read or heard it (including the quote, if possible).


not being in agreement or harmony

Get Word of the Day daily email!

Test Your Vocabulary

Confusing Words—A Quiz

  • alice with tweedle dee and tweedle dum
  • I invented a brand new toaster robot and ______ it "Sir Toasts-a-Lot."
Spell It

Can you spell these 10 commonly misspelled words?

Add Diction

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!